


Just us

by CherryPie0



Category: Marvel Cinematic Universe, Thor (Movies)
Genre: Accidental Voyeurism, Alternate Universe - Human, Alternate Universe - Teenagers, F/M, Female Loki (Marvel), First Time, Hand Jobs, Masturbation, Sibling Incest, Smut, Vaginal Fingering, Vaginal Sex, Virgin Loki (Marvel), unprotected sex
Language: English
Status: Completed
Published: 2018-12-10
Updated: 2018-12-10
Packaged: 2019-09-15 02:20:15
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,792
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16924695
Author URL: https://archiveofourown.org/users/CherryPie0/pseuds/CherryPie0
Summary: After seeing his little sister naked, it's all Thor can think about, making his forbidden thoughts even harder to get rid of. He thinks that avoiding Loki might be the best thing he can do, so he tries to stay away.Unsurprisingly, Loki doesn't seem very fond of his plan.





	Just us

Thor heads to his sister's room to ask her if she wants to fix her something to eat, since their parents work late tonight so he's usually responsible for dinner. If it was up to Loki they'd probably starve to death. Not that Thor minds, anyway; he likes to take care of her. She is his little sister, after all.

He finds her door slightly open so he decides to just step inside, assuming there's no need to knock since the door hasn't even been closed. He grips the knob and is about to push it open when his eyes land on his sister's slim figure, having just gotten out of the shower, a white towel wrapped around her body while her damp black hair fall over her shoulders. 

His hand stills on the knob of the door when he sees her unwrap the towel, letting it fall on the bed behind her, leaving her completely naked. He hasn't seen her like this since they were little kids and used to bathe together, and he feels his breath getting caught in his throat at the sight.

He wants to leave or at least force his eyes to keep looking at the back of her head, or even better not at her at all but he can't help following the little drops of water that drip down from her hair and slide on her creamy skin, reaching the small of her back and then the swell of her ass. His eyes focus on the round cheeks, looking smooth and pale like the rest of her, immediately putting thoughts in his head that he constantly has to fight to push away. 

He feels his mouth go dry as he keeps looking, wishing his eyes wouldn't blink at all so he won't miss even a second of this. He has to bite his lip to prevent the moan that wants to escape when Loki bends down to pull her panties on, giving him a clear view of her cunt, pink soft folds having Thor's cock swell with arousal so quick that he almost feels dizzy. 

Loki slides on her black panties, the color creating a delicious contrast with the paleness of her skin, and Thor is sure that his little sister is the most gorgeous thing he's ever seen. 

She turns slightly around to grab her t-shirt and Thor's eyes widen, afraid for a second that she saw him but his fear disappears only a moment later when his eyes fall on her breasts. He doesn't have a full view from this angle but it's more than enough to have his heart pounding in his chest and his cock throb in his pants. They're small and round and absolutely perfect, with pink little nipples that right now seem perky and hard, most likely because of the cool air in the room hitting her damp skin. 

Thor has always found his sister pretty, probably thinking about it much more than a brother should, but right now he's struck by how really breathtaking she is, how beautiful and perfect she is in ways he couldn't even imagine. 

Suddenly he realises that she's almost done getting dressed and he gingerly lets go of the door knob, pulling away silently and walking to his room with shaking legs and his cock fully hard and leaking in his boxers. He closes the door of his room and leans back against it, letting out a stuttered breath that he's been holding for the last few minutes, his hand traveling down his pants of its own accord.

He slips his hand inside his boxers and palms himself, gathering the precum with his thumb and spreading it along the hard length, allowing his hand to move more smoothly as he starts stroking himself. Unsurprisingly, all he can think about is his little sister; it's not the first time, of course, but it never was after just having seen her naked and everything feels even more intense.

He thinks about touching her and exploring her body with gentle hands, kissing her pretty lips softly, cupping her ass in his palms, playing with her nipples using both his fingers and his mouth. He imagines how it would feel if he let his hand slide all the way down between her legs so he could tease her clit before easing a finger inside her, and he can't help but wonder how wet she'd be for him and if she would let him taste her. 

He's sure she would taste so sweet that he would get addicted to her taste as he is now to her lovely scent. With the thought of having his mouth on his little sister's cunt and making her moan and come for him, he reaches his climax and his orgasm hits him hot and blinding, and he has to bite his lip to muffle his moans. 

His cock pulses in his hand as it keeps spilling inside his boxers, leaving Thor panting and overwhelmed. He's sure he hasn't come so hard since the first times he had started jerking off, years ago. 

He slides down and sits on the floor, letting his head fall back on the door when he's done, feeling like his legs can't hold him up anymore, trembling both from his orgasm and the usual guilt that comes every time he orgasms with thoughts of his sister. He squeezes his eyes close and takes a deep breath to calm himself down so he can get up and go clean himself up, before he has to go out and face his little sister, pretending that he didn't just come with her name silently on his lips.

**

It's been two weeks since that evening and Thor hasn't managed to take his mind off those thoughts even for a second. They have him hard and panting every night before he comes and his arousal is gone, leaving him feeling sick in his stomach until he finally falls asleep. It actually seems to be getting worse amd worse every day and he can hardly meet his sister's eyes anymore. 

He hoped that at least the change in his behavior is subtle enough to not raise any questions but, of course, Loki has noticed and the last couple of days gives him suspicious looks when Thor acts too weird. 

He has been trying to spend as less time as possible alone with Loki in the house, but tonight their parents are going out and Thor is dreading every single minute that will follow. It used to be his favorite thing, having his little sister all to himself and he hates that he's ruined it 

He almost starts sweating from nervousness the moment their parents are out of the door, and he decides to just lock himself in his room, ready for a hopefully uneventful evening. He stays there for the first hour, until his stomach starts growling and he has to get out of his room to eat something. 

This time instead of going to Loki's room to ask her, he yells from the hall, receiving a 'no thanks' as an answer. He might have been avoiding for days but he still wants to make sure that she's eaten something.

He's making a sandwich when Loki shows up, letting out a frustrated sigh. 

"Thooooor, have you seen my grey shorts anywhere? I can't find them. Where did mom put them?" she grumbles as she enters the kitchen. 

"No, I-" Thor chokes on his words when he makes the mistake to turn his head and look at her, seeing her shuffling in the kitchen, wearing only a big green t-shirt that Thor recognizes as his own , one that had stopped fitting him a couple of years ago but it's still big and long enough that Loki is basically swimming inside of it, with it reaching down to her thighs. He clears his throat and averts his gaze, feeling his face flush. It's not the first time he sees Loki like that but after the last two weeks it's almost too much. "I haven't seen them anywhere, sorry," he says, keeping his voice as steady as he can, returning his attention to his sandwich. 

He feels Loki's eyes on him and he prepares himself for her reply but, thankfully, she doesn't call out on his suspicious behavior.

"Okay," she says simply, before disappearing in her room and Thor lets out a relieved breath. 

He sits on the couch to eat, turning the tv on, only to regret not going to eat to his room a few minutes later. Loki comes back - this time wearing shorts, too, so that's something, - and sits across him on the couch. They just sit silently for a while, the only sound in the room coming from the TV, before Loki lets out a sigh and turns her eyes on him. 

"Is something wrong? And don't lie to me; don't think I haven't noticed that you've been acting weird lately. What is it?" She asks and Thor feels his whole body tensing as he turns to look at her, meeting her gaze. 

"What? Nothing, everything's fine. I've just been busy lately," he replies, as convincingly as possible, which doesn't seem to be enough because Loki raises a questioning eyebrow at him.

"Sometimes I feel like you're avoiding me... Did I do something?" This time her voice is smaller, sounding unsure and Thor absolutely hates it. He can't let his sister feel guilty because of his own disgusting thoughts. 

"Hey, no, you did nothing, Lo. It's nothing, really, you don't have to worry about anything, I promise," he says and offers her a smile, his most genuine in those last weeks. Loki narrows her eyes and looks at him for a few seconds, like she tries to figure out if he's saying the truth before her lips start curling into a smile. 

"Okay, I'll let it go, for _now_ ," she says and shuffles closer to him on the couch until their arms are brushing together. "What are you eating?" She asks but before he has any time to answer, she has already grabbed the sandwich from his hand to take a bite. Thor can't even pretend to be angry at her; he has missed being so close to her these days that he has been avoiding her and right now he can only smile fondly at her, feeling his heart swell with affection.

"Stop eating my sandwich, I'll make you another one," he says, chuckling, and takes the sandwich from her hand, grinning when she offers him a sheepish smile. 

"You're the best." She leans in and places a small kiss on his cheek, before simply resuming her position like she didn't just make Thor's breathing stop for a second or two.

Thor returns with her sandwich a few minutes later and settles next to her, smiling when she snuggles up to him and slowly starts to munch on her sandwich. 

They stay like that long after they're done eating and Loki has let her head rest on his shoulder. Thor can feel her head falling lower as she dozes off and he decides to lower them both on the couch so they're lying, making sure to leave as much space between her back and his chest as he can, which isn't a lot but still better than nothing. 

The movement wakes Loki and she yawns, before turning around and shifting closer to him. Thor lets her settle however she wants, wrapping an arm around her waist so he can stroke her back. He smiles when she makes a purring sound and nuzzles his neck, knowing how much she's always loved it when he caressed her back. 

"I like it when you touch me like that. You almost never do it anymore," she says quietly, her fingers drawing invisible circles on his collarbone through his t-shirt. Thor feels like he's having problem breathing at their proximity. 

"Do you want me to do it more?" He asks hesitantly, not quite sure how to respond to that.

"Mhm, I want you to touch me more... I want you to touch me everywhere." Her voice now is hesitant and barely a whisper but Thor hears her loud and clear, and he tenses, his hand freezing where it is on her back; she can't mean it like _that_ , can she?

"Loki...?"

"Do you not want to? The way you look at me sometimes... I thought you wanted it, too," she mumbles, her face still buried into the crook of his neck, making her voice come out a bit muffled.

"Loki... Wh- what are you saying?" He asks dumbly, knowing that he's not making this conversation any easier but he can't help it; he's still having a hard time believing that Loki means it like _that_. 

Loki is silent for a few seconds before pulling away enough so they can look at each other, and Thor fears that he ruined whatever moment they were having with his stupid questions. She locks her green eyes with his blue ones and reaches for his hand that is wrapped around her. Thor lets her move it however she wants to, even if he's afraid that she just wants to pull it off her so she can leave. Thankfully she doesn't. She grips his forearm and guides it in front of her, between their bodies.

"I'm saying _this_ ," she says as she places his open palm over her breast, placing her own hand over his and squeezing slightly, making them both gasp. Thor looks at her with wide eyes, arousal pooling down in his groin as he feels her nipple hardening beneath her t-shirt. "And _this_ ," she continues as she slides their joined hands down her body until Thor's fingers are between her slightly parted legs. "And whatever else you want," she finishes, letting their hands stay there and looking at him expectantly, her expression open and vulnerable like she's afraid that Thor will reject her. 

Thor reluctantly withdraws their hands, wanting to do this right and brings his own to her face, gently cupping her cheek. 

"Loki... Are you sure?" 

She nods and lets a small, reassuring smile form on her lips. That's all Thor needs before leaning in and closing the distance between them, sighing happily when their lips touch. It's a hesitant kiss, soft and gentle, their lips just brushing together, and yet it's more than enough to steal Thor's breath away. 

When they pull away Loki's blushing, her cheeks a lovely red color, and Thor knows that he probably doesn't look any differently. Still, there are matching wide grins on their faces and Loki giggles when she meets his eyes, before tucking her head under his chin. Thor chuckles and hugs her close to his chest, loving how she grips his t-shirt and clings to him. 

"I've wanted to do this for so long," he confesses and slightly tightens his arms around her. He feels her soft lips on his neck and he sucks in a shaky breath when she nibbles on his skin. She slowly makes her way to his jaw before connecting their lips again, this time the kiss being firmer.

Thor hesitantly licks the seam of her lips and she easily opens up for him, letting him slide his tongue inside. He licks into her mouth, stroking her tongue with his own, relishing this new sensation of feeling her lips on his own and finally knowing how she tastes. He grips the back of her neck with one hand, squeezing it gently, while her hands are on his face, cupping his cheeks and caressing his stubble with soft fingers and Thor feels like it's too much and not nearly enough at the same time.

Loki hooks one leg over his hip and shifts closer, their bodies almost completely flushed together. He tries to pull slightly away so Loki's not touching his half hard cock, not sure if it's too soon and not wanting to making his little sister feel uncomfortable. 

Loki, however, seems to have a different plan because she pushes him back until he's on his back and climbs on top of him, straddling his hips, their lips still locked. She threads his fingers through the long locks of his hair, sucking on his tongue and letting little whimpers that are probably the best thing Thor's ever heard and it makes him wonder what other sounds he can make her let out. 

He slides his hands beneath her t-shirt and runs them up and down her back, tracing her spine and feeling the goosebumps that rise beneath his touch. He lets her set the pace of their kisses and touches, not wanting to pressure her but Loki seems to be as impatient as he is. She shifts on his lap, rocking slightly her hips down against his, and Thor feels his cock growing harder beneath her weight.

He reaches between their bodies to rearrange himself, moving his cock so it's right beneath her and they both moan against each other's mouth the next time she grinds down on him. He caresses her thighs and makes his way higher so he can cup her ass, kneading the perfectly round globes in his hands, and helping her grind more firmly against him. 

They break the kiss, panting, their lips only brushing together and it feels like they're sharing the same breath, the intimacy making warmth bloom low in his belly. He relishes the weight of his little sister on top of him, both comforting and exhilarating, his cock leaking desperately from the friction.

"Thor, please. Touch me," Loki pleads in a small whine, the movements of her hips growing more urgent and desperate. 

Thor can do nothing but comply, slipping his hand between them and inside Loki's shorts, going lower when Loki spreads her legs further apart in an invitation. He rubs her over the panties and he groans deep in his throat when he feels the material soaking wet against his fingers. He presses the pads against her cunt through her panties, feeling her clenching beneath his touch but he doesn't push deeper. 

He traces up the folds with two fingers and starts rubbing her clit, making his little sister whimper beautifully against his mouth, her hands now gripping his hair firmly as she rocks her body down against his hand. 

"Don't stop, please, please, please-" Loki's voice breaks at the end and Thor feels her tense, her body almost shaking as she comes, panting, before letting her head fall on his shoulder, the only sound in the room being her heavy breathing and the TV in the background. 

He gives her time to ride out the last waves of her pleasure, caressing her hair with his free hand. 

"Are you okay?" He asks softly after a while, tilting down to press a kiss on her hair. 

"More than okay," she sighs, moving slowly so he can look at him, a lazy smile on her flushed face. "That felt really good," she mumbles and places a small kiss on his lips. "Can I...?" She asks a bit shyly, biting her bottom lip as she motions down to his lap. 

"Please," Thor nods and feels his cock throb in anticipation, his orgasm already close. "It won't take long," he tells her and she hums kind of nervously, before slipping her hand inside his sweats and boxers. She gasps when she touches him and Thor lets out a low grunt at the feeling of his little sister's fingers around his dick. 

Loki gives it a few experimental strokes before meeting his eyes, looking at him questioningly, her cheeks flushing even deeper and Thor realizes that she probably hasn't touched a cock before and that's why she looks so unsure of what she should do. Of course, he finds himself hoping that he'll be her first everything, as well; admittedly not the first time that this thought crosses his mind.

"Run your palm over the head," he instructs and she immediately does as she's told, letting out a small gasp of both surprise and wonder, probably not expecting the wetness of the precum on the head. "Yeah, that's it," he encourages as she does it again. "Now, grip me firmly and start stroking. At a steady pace, not very fast yet."

Loki listens to him carefully and obeys, having him moan in only a few seconds, her small hand doing a surprisingly amazing job jerking him off. Or maybe it's just the thought that this is _Loki_ on top of him, that this is _his little sister_ touching him and wanting to make him feel good. 

Thor slips both hands beneath her t-shirt, kneading her breasts, feeling his orgasm approach. "Fuck, like that, Lo. A bit faster, I'm close- _so_ close," he groans, the words barely having left his mouth when he starts spilling his release just as Loki tightens her hold. Loki strokes him until the last drop and Thor can only pant and moan as she milks him empty. 

"Was that good?" She asks hesitantly, looking actually slightly nervous about the answer.

Thor cups her face in his hands and pulls her closer, kissing the tip of her nose first before moving to her mouth. "It was _perfect_ ," he says - because it's the truth, that's how it felt - before kissing her lips softly but deeply, feeling like he wants to devour her.

"Thor... I wanna do more," she mumbles against his lips and Thor starts wondering if he's actually dreaming. He doesn't know how he got to be so lucky and what he did to deserve this- to deserve _her_ but he sure as hell is determined to do everything in his power to keep her now that he has her.

"Have you done anything before?" He asks as he softly strokes his thumb over her bottom lip, wanting to know how to proceed, even though he knows he'll be careful anyway.

She shakes her head, averting her gaze for a moment, like she's embarrassed. "Is that a problem?" She asks hesitantly, a slight frown forming on her face and Thor is quick to fix his mistake, not having made it clear that he'd be lucky to have her regardless her answer.

"No- God, no, Loki. First of all, you're my baby sister, I would break the hands of anyone that would dare lay a finger on you," he says sincerely, always feeling a bit overprotective when it comes to his little sister. Okay, maybe a _little_ possessive, too. 

Loki laughs and rolls her eyes, but there's a lovely blush high on her cheeks and a grin on her lips. "Brute," she mutters before kissing him and Thor is quite sure that she more than enjoys his possessiveness. "Are _you_ allowed to touch me, then?"

"If you want me to," he replies, offering her a small smile to show her that it's okay if she doesn't want anything more right now. And well, if she does want he'll be happy to oblige.

She nods and pecks his lips. "Take us to my room, please? I want my sheets to smell like you- like _us_ after we're done."

This time Thor can't help but groan at his little sister's words and he wills himself to stop shaking with excitement so he can get up. He easily lifts her up and she clings to him, legs and arms wrapped around him as he carries her to her room. 

He lowers them on the bed and she immediately spreads her legs so he can settle between them. His heart is pounding in his chest in anticipation and his cock is already stirring in his boxers. It's almost too much; having her sprawled out like that beneath him, her scent everywhere around him, her green eyes looking at him trustingly. Of all the times he has imagined it he had never thought that being able to touch her and kiss her would feel so incredibly good.

He caresses her face, his thumb stroking over her cheekbone as he leans in to kiss her, and Loki sighs into the kiss like she had missed him. She wraps one leg around his waist and her hands wonder over his back, pulling him closer to her. He slips a hand beneath the hem of her t-shirt and she shudders when he touches her flat stomach, slowly making his way higher. 

Thor can't help but moan when his hand reaches her breast and he cups it gently, easily fitting it in his big palm. He squeezes a bit more firmly and drags his thumb over her nipple a few times, smiling into the kiss when she gasps, the little nub hardening beneath his touch. 

She's impossibly soft against his slightly calloused palms, but just touching her with his hands doesn't feel enough right now. He wants to see her and to feel her skin again his own. He pulls away from the kiss and grips the hem of her t-shirt to take it off and she lifts herself to help him. Once the t-shirt is gone Thor is left staring at her, wanting to take everything in, like he's afraid that he won't have another chance to see her like that again. 

She's all pale, flawless skin, sharp collarbones that demand to be kissed, round breasts and pink nipples begging to be teased and played with.

" _Thor_ ," she whines softly and nudges his side with her knee, slightly squirming beneath him like she's trying to hide herself. And indeed when Thor's eyes finally look up at her face, her cheeks are painted an adorable pink.

"You're beautiful. The most beautiful thing I've ever seen," he tells her and even though her blush deepens - Thor is thrilled to see it spreading down her neck and collarbones - there's a wide grin on her lips now.

"Shut up," she mumbles, chuckling and Thor can't help leaning in for another kiss, wanting to taste her smile.

His hands wander all over her as they kiss, exploring every curve of her body, touching her in ways he never thought he'd be allowed to. When Loki tugs at his t-shirt Thor helps her take it off him and relishes how hungry her touches feel as she lets her hands run over his back and chest and everywhere else she can reach. 

Loki seems to grow impatient after a while because she reaches for her shorts and panties and removes them quickly, disregarding them both on the floor, leaving her completely naked beneath him. 

"Thor, please," she whispers, her voice a bit shy but her lust and need also evident in her tone.

Thor hums pleased, loving how desperate his little sister seems to be for his touch and he finally slides his hand all the way down and between her invitingly open legs. Loki digs her fingers into his shoulders when he brushes over her clit, feeling her throb at the light touch. He rubs her more firmly this time and smiles triumphantly at the small whimper that leaves her mouth.

He teases her a bit more just to hear the sinful sounds she makes, watching her pretty lips part to let out little whines and broken moans, before he lets his hand go lower. Her folds are even smoother than he was expecting and he allows himself to just feel her for a bit, sliding her fingers up and down, feeling her squirm and tense with every stroke over her folds.

He taps lightly over her opening and he grunts when he feels her wetness against his hand, smirking when she pushes down onto his touch, relishing how responsive she is to everything he does. He finally slips a finger in between her folds and she gasps but her body remains relaxed, allowing the digit to slide in smoothly.

"You're so soft... and wet," Thor rasps, feeling overwhelmed just at the thought of this tight, velvet heat around his cock. 

She whines when he starts to pump his finger in and out of her but soon she's begging for another one and Thor can do nothing but give her want she wants. He fucks her cunt with two thick digits, picking up the pace when she asks him to and adding a third finger not long after. It's a tighter fit now and Loki clenches around them before relaxing again, allowing Thor to push them inside her. 

He works his fingers in and out, coaxing her open and loose for his cock, trying his best to be patient and careful despite his dick aching and leaking in his boxers. Loki pants and moans between their kisses, sweet desperate little sounds escaping her mouth and driving Thor crazy with lust and arousal, burning with the need to know how she's going to sound when he finally fucks her. 

"Thor, come on, I'm ready. I want you inside me, brother, please," she says, her voice needy and breathless, and Thor nods and removes his fingers. 

"Condom?" He asks, having completely forgotten about it, and Loki shakes her head a bit sheepishly, shrugging slightly her shoulders. "It's okay, I have in my room-"

"No, can't you... Can't you just pull out when you're about to...?" She trails off, averting her gaze, but then continues even as her cheeks turn red. "I wanna _feel_ you inside me," she mumbles and Thor has to choke back a groan at the new wave of arousal that hits him.

"Yeah, okay, anything you want," he replies, nodding as he sits up and clumsily pulls his sweats and boxers down, turning his attention to his dick. He sighs when he releases himself from the clothes and wraps his slick fingers around his hard cock, stroking himself a few times and spreading the wetness of his sister all over his length.

He looks up at Loki and finds her curious eyes on him, watching him mesmerized as he moves his fist up and down his dick, and she flushes when she realizes that she's been caught staring. 

He chuckles softly and caresses her thigh with his free hand. "It's okay, you can look," he reassures her and Loki nods, chewing on her lower lip as she turns her attention back to his lap.

"It's... _big_ ," she murmurs, sounding both afraid and in awe, her eyes not moving away even as she speaks.

"I'll be gentle, I promise. And if it hurts at any point, you can tell me to stop, okay?" He says softly, wanting her to be relaxed and to know that her big brother will do anything to make her feel good. She finally meets his eyes and nods, smiling sweetly at him, causing the little dibble on her right cheek to appear. "I'll take care of you, Lo. Just relax, okay?"

"Okay," she breathes out, nodding again, her voice a bit shaky.

Thor returns the smile and makes a quick job removing all his clothes, before lowering himself on top of her, steadying himself on an elbow and using his other hand to line his cock up with her opening. 

Loki grips his biceps, pulling him closer and Thor ducks his head to peck her lips . "Relax," he whispers as he starts to push in.

She gasps but lets her body go lax beneath him, and they both moan when the head slips past her folds. She's still tight, impossibly tight around his thick cock, but her cunt is so warm and wet, welcoming Thor inside, and so he pushes further in.

Loki is panting heavily and despite the pain that she no doubt feels, she shifts her hips against his, trying to get him deeper inside her. 

"Okay?" Thor asks, voice rough and thick with arousal and she nods, breathing out a soft ' _please_ '. It almost feels like he's not going to fit inside her, but eventually her body gives way and he eases his cock all the way in, groaning, feeling like sliding home.

Thor stills once he's bottomed out, both for Loki's sake and his own. He's overwhelmed with the sensation of being inside his little sister and he's afraid that he's going to come way too soon if he moves now. Nothing has ever felt so good and he really wants this to last.

Loki clings to him, wrapping her long legs around his waist and bringing her hands to his back. Thor connects their lips to distract her from any discomfort she might be feeling and she sighs into the kiss, sounding grateful.

"You can move," she whispers after a while and Thor can only nod his head and oblige.

He starts moving, just small rolls of his hips that are more than enough to make both of them gasp. When he feels her loosen a bit more around him he pulls slightly out and slides back in and she bites her lip, muffling her whine.

"It's okay, I wanna hear you. You don't need to hide anything from me, Lo," he says, bringing his hand to her face to smooth the bitten lip with the pad of his thumb. She lets out a small hum and Thor watches her as she hesitantly darts her tongue out, enough to lick the tip of his thumb. His groan seems to encourage her because she wraps her lips around the digit and starts to suck on it, slick tongue lapping at it. 

Thor can only stare, captivated by the sight of his little sister, watching in awe how beautiful her lips look around his finger, admiring how hungrily she sucks on it as she hollows her cheeks around it, and all he can think is what else her mouth could do.

"Fuck, Loki, you look so lovely like that," he rasps, pressing his thumb down against her tongue. "I'd love to see those lips stretched around my cock. Would you like that, Lo?" Loki nods and whines around the finger, sucking more eagerly like she imagines that it's his cock instead. "You'd let me fuck your pretty mouth, wouldn't you, sweetheart?" He asks and he knows he should feel dirty and guilty for talking to his little sister like that but he can only feel his arousal growing stronger as she moans needily, clenching slightly around his cock that is now sliding slowly in and out of her.

She gasps when he pulls his thumb out of her mouth, smearing saliva all over her pink lips. "Harder- fuck me harder," she demands, urging his hips to move faster with her legs that are wrapped around him.

Thor grunts and picks up his pace, thrusting inside her a bit harder. She's still deliciously tight around him, but now he can slide in and out smoothly, filling her to the hilt when he pushes all the way in, eliciting more and more broken whimpers from his sister. 

He lets his eyes wonder over Loki's body, his cock throbbing inside her at the sight. She looks so delicate and fragile beneath him as he covers her body with his much larger frame. He could easily crush her- break her, but she looks relaxed in his arms, like she feels safe there. He hopes she does.

He leans closer and noses at her cheek, kissing her jaw and making his way to her neck, pressing kisses to her soft skin, sucking flesh into his mouth, determined to leave his marks everywhere on her body, to stake his claim on her.

"Fuck, Thor," Loki moans when he bites down on the spot where her neck connects with her shoulder and she clenches around him, her nails digging in his back, no doubt leaving scratches and Thor is more than happy to have her marks on his body. He is _hers_ as much as she is _his_. 

Loki has started shifting her hips to meet his thrusts halfway so he quickens his pace, moving his hands to grip her under her thighs, pushing her legs up so he can dive deeper inside her. "You feel so good, so fucking good," he groans as he slams into her, making slick filthy sounds as his cock slides in the delicious wetness between her legs. "You take me so well, sister... like you were made to take my cock," he continues shamelessly now, feeling delirious with burning desire and overwhelming pleasure. 

Loki mewls and squirms beneath him, repeating his name in that delicious broken voice of hers that has Thor thrusting harder into her cunt. Her breasts bounce beautifully as he pounds into her and he can't help but want to touch them. He frees one of her thighs and moves his hand so he can play with her, squeezing one round breast in his large hand, before letting go of it, rubbing her hard nipple instead, pinching it between two fingers. 

"Thor, please, please, please. I'm- I'm close. Brother, please," she sobs out desperately and Thor is sure that he's never heard anything more beautiful.

"Come on, touch yourself, Lo. I want you to come for me," he says, now slamming into her wet heat almost brutally, eliciting a cry of pleasure from his sister with every greedy thrust of his hips. 

Loki reaches between their bodies and starts rubbing at her clit, like he asked her to, small choked whimpers leaving her mouth as she approaches her climax. It's not long before he feels her tensing and shaking against him, her legs tightening around his waist while her cunt convulses around his cock as she comes. Thor fucks her through it, relishing all her beautiful cries and the way her lips part around his name, looking sinful and like heaven at the same time. 

He pounds into her until she rides out the last waves of her orgasm and collapses boneless on the sheets, her body pliant in Thor's hold. He feels his own climax coming and he thrusts a few more times inside her before reluctantly pulling out and sitting up between her open legs, making Loki whine at the loss. 

His cock is shining with his sister's slickness and his fist slides easily as he starts stroking himself. "Look how wet you are for your big brother, sweetheart," he grunts, pointing down to his dick, and Loki looks, flushing a deep red, but doesn't avert her gaze. She stares at it with dark eyes, like she's hungry for it, even though she just had it inside her. "You liked that, Lo? Having my fat cock in your sweet little cunt?"

She nods, instinctively arching her back and pushing her breasts up, driving him closer to the edge. "I loved it. Felt so good inside me, brother," she says in a soft whimper, licking her lips slowly as she meets his eyes. 

That's all Thor needs before he starts coming, letting out a deep groan, his cock pulsing in his hand as it spills white pearls of cum all over her stomach and breasts, creating a rather breathtaking sight. He wipes the head against her thigh when he's done and leans down to lick his own cum off her, dragging his tongue greedily over her breasts and nipples.

" _Thor_ ," Loki gasps, sounding both surprised and aroused, and Thor can't help but chuckle, pulling away so he can kiss her on the lips. Another gasp leaves her mouth when she tastes Thor's cum and she sucks on his tongue like she wants to take more of it. 

"Fuck, you're perfect," Thor rasps against her mouth and pecks her lips again and again, not able to get enough of her. He finally settles on the bed beside her and pulls her closer to him until she's lying on his chest. She hums contently when he cradles her head, gently stroking her hair. 

"That was nice," Loki says a bit shyly and Thor chuckles, shaking his head fondly; _nice_ , she says. "When can we do it again?"

"Whenever you want," he replies and can't help feeling relieved and incredibly happy that Loki hasn't regretted and wants it to happen again. 

"Now?" She asks enthusiastically, tilting her head up to look at him with hopeful eyes and Thor laughs, amused by her eagerness.

"I'm afraid I'm gonna need a few minutes before we go again," Thor says, offering her a sheepish smile.

"Mm okay," Loki mumbles and pecks his lips. "Wake me up when you're ready, then." She resumes her position, nuzzling into his chest and getting comfortable, making an affectionate smile form on Thor's face. With her warm, soft body pressed against him, Thor is sure he'll have to wake her sooner rather than later. He doubts that she'll mind, anyway.

**Author's Note:**

> Thank you for reading!! Feedback is always greatly appreciated!!❤️


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